Methods for managing neighbor relations and coordinating physical cell identifiers for moving high altitude platform systems

ABSTRACT

Systems, methods, apparatuses, and computer program products for managing neighbor relations and coordinating physical cell identifier (PCIs), for example, for moving high altitude platform systems are provided.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority from U.S. Provisional Application No.63/010,811, filed on Apr. 16, 2020. The entire contents of this earlierfiled application are hereby incorporated by reference in theirentirety.

FIELD

Some example embodiments may generally relate to mobile or wirelesstelecommunication systems, such as Long Term Evolution (LTE) or fifthgeneration (5G) radio access technology or new radio (NR) accesstechnology, or other communications systems. For example, certainembodiments may relate to systems and/or methods for managing neighborrelations and coordinating physical cell identifier (PCIS), forinstance, for moving high altitude platform systems.

BACKGROUND

Examples of mobile or wireless telecommunication systems may include theUniversal Mobile Telecommunications System (UMTS) Terrestrial RadioAccess Network (UTRAN), Long Term Evolution (LTE) Evolved UTRAN(E-UTRAN), LTE-Advanced (LTE-A), MulteFire, LTE-A Pro, and/or fifthgeneration (5G) radio access technology or new radio (NR) accesstechnology. 5G wireless systems refer to the next generation (NG) ofradio systems and network architecture. A 5G system is mostly built on a5G new radio (NR), but a 5G (or NG) network can also build on the E-UTRAradio. It is estimated that NR provides bitrates on the order of 10-20Gbit/s or higher, and can support at least service categories such asenhanced mobile broadband (eMBB) and ultra-reliablelow-latency-communication (URLLC) as well as massive machine typecommunication (mMTC). NR is expected to deliver extreme broadband andultra-robust, low latency connectivity and massive networking to supportthe Internet of Things (IoT). With IoT and machine-to-machine (M2M)communication becoming more widespread, there will be a growing need fornetworks that meet the needs of lower power, low data rate, and longbattery life. The next generation radio access network (NG-RAN)represents the RAN for 5G, which can provide both NR and LTE (andLTE-Advanced) radio accesses. It is noted that, in 5G, the nodes thatcan provide radio access functionality to a user equipment (i.e.,similar to the Node B, NB, in UTRAN or the evolved NB, eNB, in LTE) maybe named next-generation NB (gNB) when built on NR radio and may benamed next-generation eNB (NG-eNB) when built on E-UTRA radio.

BRIEF DESCRIPTION OF THE DRAWINGS

For proper understanding of example embodiments, reference should bemade to the accompanying drawings, wherein:

FIG. 1 illustrates an example of a PCI collision problem;

FIG. 2 illustrates an example of a PCI confusion problem;

FIG. 3 illustrates an example terrestrial network with hexagonal cells,according to an embodiment;

FIG. 4a illustrates an example flow diagram of a method, according to anembodiment;

FIG. 4b illustrates an example flow diagram of a method, according to anembodiment;

FIG. 5a illustrates an example block diagram of an apparatus, accordingto an embodiment; and

FIG. 5b illustrates an example block diagram of an apparatus, accordingto an embodiment.

SUMMARY

According some aspects, there is provided the subject matter of theindependent claims. Some further aspects are defined in the dependentclaims. The embodiments that do not fall under the scope of the claimsare to be interpreted as examples useful for understanding thedisclosure.

In a first aspect thereof the exemplary embodiments of this inventionprovide a method that comprises receiving, at a first network node,geolocation information for at least one second network node; managing,by the first network node, relations of neighbor network nodes of thefirst network node and/or the at least one second network node; andresolving physical cell identifier problems using the geolocationinformation.

In a further aspect thereof the exemplary embodiments of this inventionprovide an apparatus that comprises at least one processor; and at leastone memory comprising computer program code, the at least one memory andcomputer program code are configured, with the at least one processor,to cause the apparatus at least to receive geolocation information forat least one first network node; manage relations of neighbor networknodes of the apparatus and/or the at least one first network node; andresolve physical cell identifier problems using the geolocationinformation.

In another aspect thereof the exemplary embodiments of this inventionprovide a computer program embodied on a non-transitorycomputer-readable storage medium. The computer program comprisingprogram code for controlling a process to execute a process. The processcomprising receiving, at a first network node, geolocation informationfor at least one second network node; managing, by the first networknode, relations of neighbor network nodes of the first network nodeand/or the at least one second network; and resolving physical cellidentifier problems using the geolocation information.

DETAILED DESCRIPTION

It will be readily understood that the components of certain exampleembodiments, as generally described and illustrated in the figuresherein, may be arranged and designed in a wide variety of differentconfigurations. Thus, the following detailed description of some exampleembodiments of systems, methods, apparatuses, and computer programproducts for managing neighbor relations and coordinating physical cellidentifier (PCIS) for moving high altitude platform systems or aerialbase stations, is not intended to limit the scope of certain embodimentsbut is representative of selected example embodiments.

The features, structures, or characteristics of example embodimentsdescribed throughout this specification may be combined in any suitablemanner in one or more example embodiments. For example, the usage of thephrases “certain embodiments,” “some embodiments,” or other similarlanguage, throughout this specification refers to the fact that aparticular feature, structure, or characteristic described in connectionwith an embodiment may be included in at least one embodiment. Thus,appearances of the phrases “in certain embodiments,” “in someembodiments,” “in other embodiments,” or other similar language,throughout this specification do not necessarily all refer to the samegroup of embodiments, and the described features, structures, orcharacteristics may be combined in any suitable manner in one or moreexample embodiments.

Additionally, if desired, the different functions or proceduresdiscussed below may be performed in a different order and/orconcurrently with each other. Furthermore, if desired, one or more ofthe described functions or procedures may be optional or may becombined. As such, the following description should be considered asillustrative of the principles and teachings of certain exampleembodiments, and not in limitation thereof.

Certain embodiments described herein can address at least the problem ofmanaging neighbor relations and X2 interfaces and allocating physicalcell identifier (PCIS) in the case of moving high altitude platformsystems/stations (HAPS) using the same frequency as the terrestrialnetwork. It is noted the example embodiments are not just applicable toHAPS, as certain embodiments may similarly be applied to drones withflying base stations or aerial access points. As such, according to someembodiments described herein, a HAPS may alternatively be a flying basestation or aerial access point. Further, it should be noted that exampleembodiments discussed herein are described with LTE terminology;however, example embodiments are equally applicable to 5G and otherfuture systems as well.

High Altitude Platform Systems (HAPS) refer to a new telecommunicationinfrastructure solution for rural and remote areas, as well as toprovide extra capacity or as a backup solution (e.g., in caseterrestrial networks fail) in other areas such as urban areas, based onstratospheric airborne platforms. The HAPS are proposed to operate ataltitudes between, for example, 3 to 22 kilometers (km) to cover aservice area up to 1,000 km diameter and 800,000 square km depending onthe minimum elevation angle accepted from the user's location. HAPS canbe based on balloons or on solar powered high-altitude planes.

HAPS are covered in the 3^(rd) generation partnership project (3GPP)under the Non-Terrestrial Networks (NTN) work item (WI), which alsocovers low earth orbit (LEO) and geostationary (GEO) satellites, inaddition to HAPS. The issues specifically mentioned in the WI related toHAPS include co-existence with terrestrial networks. The co-existenceissues arise from the desire to operate the HAPS as part of the samepublic land mobile network (PLMN) on the same frequency as theterrestrial network.

It is typically assumed that the HAPS fill coverage holes of theterrestrial networks, and create negligible interference to the areascovered by the terrestrial network. However, handovers betweenterrestrial cells and HAPS are relevant. For example, handover from HAPSto terrestrial cell may be performed to rescue UEs from terrestrialinterference, and handover from terrestrial cell to HAPS may beperformed to rescue UEs from terrestrial coverage hole.

Proper handover performance is only achieved if the source cells haveproper neighbor cell lists, i.e., if the target cells are well plannedwith regards to their Physical Cell Identifier and the source cell knowsthe global cell ID (ECGI)—of the neighboring cells. Then, the sourcecell can initiate proper handovers to correct target cells.

It is also important to note that the HAPS are moving (in contrast toterrestrial base stations), but not necessarily in a recurring andpredictable way (in contrast to satellite nodes).

Physical Cell identifiers (PCIs) typically have two sometimescontradicting targets. First, PCIs have to be short in order to ease thedetection for the terminal (e.g., UE). It is noted that in most casesthe cell identifiers are coded into the reference (pilot) signals thatare used for cell detection. So, PCIs have to be read without knowinganything from a cell, without being able to estimate the channel, andwithout having synchronization to a cell. This makes the PCI detection arather complex hypothesis test. Additionally, PCIs should be unique in alocal neighborhood. A large set of PCIs (i.e., long identifiers) may beneeded for this purpose.

This uniqueness requirement implies two conditions that could result inPCI collision and PCI confusion, as discussed in more detail in thefollowing. Obviously, neighbors must have different PCIs, otherwise theycannot be distinguished. Violation of this condition may be referred toas PCI collision. FIG. 1 illustrates an example of a PCI collisionproblem. Enhanced cell global identifier (ECGI) is the LTE terminologyfor a global (i.e., unique) cell identifier, which is too long for celldetection. As illustrated in the example of FIG. 1, the terminal 101 mayinterpret ECGI3 as an echo of the own signal, i.e., the terminal 101would not even realize that there is another cell. At some point, theterminal 101 may drown in the interference of ECGI3 and therefore maysuffer a failure (e.g., radio link failure).

Less obviously, neighbors of neighbors must also have different PCIs.Violation of this condition may be referred to as PCI confusion. FIG. 2illustrates an example of the resulting PCI confusion problem, where thetwo cells ECGI1 and ECGI3 have the same PCI1. As illustrated in theexample of FIG. 2, the UE 201 may move from cell ECGI2 to ECGI3 and mayreport PCI1. The serving cell ECGI2 does not know to which cell itshould initiate the handover. Therefore, it may initiate the handover toECGI1, which will obviously result in a failure.

Unfortunately, in real terrestrial networks, it is not obvious at allwhich cells have a neighbor relation. For instance, in networks with avery dense deployment, a single cell may have more than 50 neighbors.This is a result of unexpected propagation such as coverage overshots offar distant cells. As a result, the expression “neighbor relation” has amore abstract meaning, far beyond a pure geographical meaning, at leastin classical terrestrial networks; this is why network planning alonecannot solve the neighbor relation problems and/or PCI problemsreliably, and neighbor relation problems and/or PCIs have to beoptimized and/or corrected dynamically during operation.

An early observation can be made that neighbor relation problems and/orPCI problems in classical terrestrial networks arise from unpredictablepropagation (although base stations are static). Current solutions aretailored to this assumption. HAPS, however, have predominantlyline-of-sight connections, and thus propagation is well predictable;HAPS are moving across the terrestrial cells, which also requiresneighbor relation/PCI optimization and/or correction during operation,but due to completely different reasons and therefore solutions may alsolook different.

In the following, the occurring problems with neighbor relations andPCIs will be described in more detail. For these purposes, as anexample, it is assumed that HAPS will be dedicated an exclusive set ofPCIs. This simplifies the problem massively without introducing severrestrictions to PCI allocation. For instance, as one example, with 504existing PCIs (as an LTE example), the terrestrial cells may use PCI 1 .. . 470, whereas HAPS may use PCI 471 . . . 504. This is typicallycalled PCI fragmentation.

FIG. 3 illustrates an example terrestrial network with (small) hexagonalcells. In this example, PCIs have been assigned to the relevantterrestrial cells. For the sake of simplicity, the example of FIG. 3shows the coverage area of a single HAPS which is flying from the leftto the right across the terrestrial network.

The coverage of the HAPS is much larger than that of a terrestrial cell(in reality it will be even much larger than shown in the example ofFIG. 3). With the above assumption of PCI fragmentation, there willnever be a PCI collision between terrestrial cell and HAPS. However, thefollowing neighbor relation/PCI problems may still occur. Newterrestrial cells are covered (e.g., cell 13), and new neighbourrelations are needed. “Old” terrestrial cells leave the HAPS coverageand shall be removed (e.g., cells 2, 19). New terrestrial cells may havethe same PCI as an existing PCI (e.g., cells 1). This may lead to PCIconfusion. This indicates again the importance of deleting “old” cellsas soon as possible. A HAPS may persistently cover multiple terrestrialcells with same PCI (e.g., cells 3), which leads to unavoidable PCIconfusion. It seems impossible that the terrestrial PCI allocationavoids this confusion, at least if the HAPS coverage approaches 504terrestrial cells (504 is the number of available PCIs in LTE). As such,a work around for this PCI confusion needs to be found.

There are also the typical PCI problems among the HAPS (PCI collisionand confusion). However, example embodiments can also solve the PCIproblems between HAPS as explained in more detail below.

Additionally, it is also desirable to avoid impact to terrestrialnetworks as much as possible. For example, new functionality in theterrestrial network should be minimized and new functionality should bepredominantly in the HAPS, as the number of HAPS cells is expected to bemuch lower than the number of terrestrial cells.

As mentioned above, current solutions to the neighbor relation and PCIproblem are tailored for terrestrial networks with static base stationsand unpredictable propagation. When network planning for terrestrialnetworks, as a first step, the PCI allocation and neighbor relations arepre-planned as well as possible before the network is rolled out orbefore additional cells are installed. This is based on geographicalcoordinates and appropriate propagation models. Geographical coordinatesare well-known and fixed, but propagation models are never perfectlyaccurate and propagation may even change over time (buildings might beadded or removed, trees have falling leaves). Hence, for suchterrestrial networks, the planned neighbor relations/PCI allocation isnever perfect and dynamic PCI optimization/correction is needed as wellas optimization of neighbor relations. This may also be referred to asautomatic neighbor relation (ANR).

Instruments for dynamic ANR and PCI optimization and/or correction mayinclude: ECGI reading by UEs, operation and maintenance (OAM) resolutionof unknown PCI, Exchange of PCIs via X2 (e.g., via “eNB configurationupdate” message), network optimization through handover statistics,and/or network listening mode with Home base stations (HeNB).

Using ECGI reading by UEs, missing neighbor relations can be resolved.To do so, initially, the UE reports a PCI which is not known to the basestation, i.e., the base station may not have an X2 interface and may notknow which cell exactly (i.e., which ECGI or IP address) the UE shouldhandover to. In this case, the base station may instruct the UE to readthe ECGI of the unknown neighbor. The UE has to synchronize to theneighbor (detaching temporarily from the old cell), read the ECGI (whichis part of the system information), return to the serving cell andreport the ECGI reading. However, this approach has several drawbacks.For example, the feature may not be implemented by all UEs. Furthermore,it introduces unnecessary interruption to the UE where it has to detachand return, which also risks a failure. Finally, this will only solvethe problem of missing neighbor relations, but not of PCI collision andconfusion.

With OAM resolution of unknown PCI, instead of contacting the UE forretrieving the ECGI of an unknown neighbor, a UE may contact OAM. Inturn, OAM may resolve the PCI using its global geometrical informationof all cells in the network and other available information. Forinstance, OAM may determine the ECGI of the cell with the reported PCIwhich has the shortest distance to the cell that has requested the PCIresolution. However, this is typically not real-time. Hence, thisapproach can help in the long-term, but not for the UE at hand. As aresult, OAM resolution is not helpful for the moving HAPS case.

With respect to the exchange of PCIs via X2, base stations can exchangeinformation about their neighbors via X2 interface. More precisely, abase station may send PCI/ECGI pairs of its neighbors to a neighboringbase station. This can be helpful to resolve unknown PCIs, may help todetect PCI confusion, etc. The corresponding message transmitted via X2may be called “eNB configuration update” in LTE; however, as exampleembodiments are not limited to LTE, other terminology can be usedaccording to certain embodiments, such as, but not limited to,“configuration update message.”

With respect to network optimization through handover statistics,network management can regularly evaluate handover statistics. Thisevaluation may also reveal PCI issues, such as where certain Radio LinkFailures (RLF) may reveal PCI collision (PCI before and after failureare the same), certain Handover Failures may reveal PCI confusion,and/or no activity on a cell boundary (i.e., no handovers) may revealthat a neighbor relation is obsolete and should be removed. However,these methods are also reactive and assume stationarity. Therefore,these methods would also not be applicable for moving HAPS.

HeNBs were designed to be installed without any planning (since theirlocation was out of the control of the operator). Before switching theirdownlinks on, HeNBs could act as a UE measuring surrounding PCIs. Forinstance, a HeNB may pick a PCI that was not measured. It is noted thata base station cannot perform UE-like measurements without deactivatingits downlink. Hence, for a moving HAPS, this procedure would need to berepeated regularly causing massive outage for the whole cell.Consequently, network listening mode by a base station is also onlyappropriate for static base stations. Furthermore, it does not solve theproblem reliably, since it only takes measurements at the location ofthe base station (e.g., at the HAPS), which is not very relevant.Moreover, PCI confusion cannot be addressed with such a method.

As introduced above, there are important differences betweenconventional terrestrial networks and HAPS. For terrestrial networks,cell locations are static. Whereas, for HAPS, locations varycontinuously. On the other hand, propagation between HAPS and UEs ismuch more predictable than between terrestrial cells and UEs (mainlyline-of-sight (LOS) connection).

As will be discussed in more detail below, certain embodiments providethat base stations or other centralized entities exchange globalpositioning system (GPS) coordinates of neighbors for ANR and PCIoptimization. In one embodiment, a first network node (e.g., HAPS,terrestrial or flying base station) may receive geolocation information(e.g., GPS coordinates) about one or more second network node(s) (e.g.,a terrestrial base station or another HAPS) from a third network node(e.g., another HAPS, a terrestrial base station, a centralized entity,or HAPS manager). According to some embodiments, the second network nodeand the third network node may be the same node or different nodes.Receipt of the geolocation information about the second network node(s)may assist the first network node to manage its neighbor relations(e.g., to add/remove neighbor relations in terms of PCI/ECGI pairs orPCI/IP address pairs, add/remove X2 connections, etc.), and to resolvePCI problems. Additionally, in an example embodiment, the first networknode may receive further geometrical instruction (e.g., aminimum/maximum distance) from a fourth network node (e.g., HAPSmanager, OAM, or the third network node) determining the strategy tomanage neighbor relations. Furthermore, in some embodiments, the firstnetwork node may inform the second or third network node(s) that theneighbor relation to the second network node is no longer relevant(e.g., the second network node is no longer in the coverage of the firstnetwork node).

Referring again to the example depicted in FIG. 3, according to anembodiment, the X2 information “eNB Configuration Update” may beextended to include GPS coordinates. For example, in one embodiment, aterrestrial base station or eNB/gNB may send GPS coordinates of itsneighboring terrestrial base stations or eNBs/gNBs (along with theexisting PCI/ECGI) and its own coordinates to a HAPS neighbor.

With this received information, the HAPS can resolve all problemsdiscussed above, such as PCI collision and PCI confusion problems, andneighbor relation problems. In an embodiment, from the PCI/ECGI/GPSlists received from all existing terrestrial neighbors, the HAPS mayrecognize non-existing neighbors. For instance, according to the exampleof FIG. 3, cell 13 will show up in the X2 message of cell 9 or 10. Basedon the GPS information, the HAPS can decide whether cell 13 shall beadded immediately, later on, or not at all. It is noted, that “addingcell 13” may mean setting up an X2 interface and updating the neighborcell list.

In an embodiment, based on the GPS information, the HAPS can also removeexisting neighbors, if the distance increases the estimated HAPScoverage (e.g., 2). This decision may be simplified, if the HAPS knows aminimum distance between two terrestrial cells with the same PCI. Ifthis minimum distance is large, then it can keep neighbor relationslonger as this does not create any harm. If the minimum distance isshort, then the HAPS may possibly delete neighbor relations earlier. Asan example, if the minimum distance between terrestrial nodes with samePCI is, e.g., 120 km, and the HAPS coverage has a diameter ofapproximately 80 km, then the HAPS can safely keep the neighbors beyonda distance of 40 km (measured from the cell center) and release themonly at a distance of 60 km, without having risk of PCI confusion andmissing neighbor relation. Without this information, the HAPS may haveto delete it at 40 km distance to avoid risk of PCI confusion, howeverwhich may increase the risk of missing neighbor relation.

Still referring to the example of FIG. 3, in the X2 message of cell 10,the HAPS may recognize that there is a new ECGI with new GPScoordinates, but with the same PCI (e.g., cell 1) as an already existingcell. As a result, the HAPS is aware of a PCI confusion. In the case ofcell 1, the HAPS may decide, based on the GPS coordinates, to delete theneighbor relation to avoid the PCI confusion (since the old cell 1 isalmost gone). In case of cell 3, the PCI confusion is more persistentsince both cells with PCI 3 are relevant. Nevertheless, provided theHAPS has at least very rough location information of the UEs, it isstill able to resolve, from the PCI, the ECGI and thereby the correct X2interface for the handover. In some examples, the rough locationinformation of the UEs can be obtained either by GPS coordinatesreported by the UEs, or by radio frequency (RF) finger prints (e.g., UEmay have previously reported measurements from PCI 11 and 6, then HAPSknows it is the bottom cell with PCI 3).

FIG. 4a illustrates an example flow diagram of a method for managingneighbor relations and coordinating PCIs for HAPS, according to oneexample embodiment. In an example embodiment, the flow diagram of FIG.4a may be performed by a network entity or network node associated witha communication system, such as LTE or 5G NR. For instance, in someexample embodiments, the network node performing the method of FIG. 4amay include a base station, eNB, gNB, NG-RAN node, and/or a highaltitude platform station. Thus, in one example embodiment, the methodof FIG. 4a may be performed by a HAPS.

As illustrated in the example of FIG. 4a , the method may include, at400, a HAPS receiving geolocation information, such as GPS coordinates,of one or more network node(s). The network node(s) may include aterrestrial base station or another HAPS. The receiving 400 of thegeolocation information may include receiving the geolocationinformation from another network node, such as another HAPS, aterrestrial base station, a centralized entity, or a HAPS manager. Forexample, the receiving 400 may include receiving the geolocationinformation of the another network node and/or the geolocationinformation of nodes neighboring the another network node. For example,in one embodiment, the receiving 400 may include receiving, from aterrestrial base station or eNB/gNB, GPS coordinates of neighboringterrestrial base stations or eNBs/gNBs, along with the PCI/ECGI and theGPS coordinates of the terrestrial base station/eNB/gNB. In certainembodiments, the method may include, at 405, storing the receivedgeolocation information.

As further illustrated in the example of FIG. 4a , the method may alsoinclude, at 410, managing relations of neighbor network nodes and/orresolving PCI problems, using at least the received geolocationinformation. For example, the PCI problems may include PCI collisionand/or PCI confusion. For example, the managing 410 may include usingthe received geolocation information to add or remove neighbor relationsin terms of PCI/ECGI pairs or PCI/IP address pairs and/or to add orremove X2 connections.

In some embodiments, the receiving 400 may further include receivinggeometrical instruction, such as a minimum or maximum distance, fromanother network node, such as a HAPS manager or OAM, which may determinethe strategy to manage neighbor relations. In an embodiment, the methodmay include informing one or more network node(s) when the neighborrelation to those network node(s) is no longer relevant. For instance,the neighbor relation may be considered no longer relevant when thenetwork node(s) are no longer in the coverage of the HAPS or are not inthe direction of movement of the HAPS. According to certain embodiments,the receiving 400 may include receiving the geolocation informationand/or geolocation instruction in a configuration update message via X2.For example, in an embodiment, the X2 information configuration updatemessage may be extended to include, in addition to PCI and ECGI, GPScoordinates and/or geolocation instructions. In some embodiments, thestoring 405 may include storing the geolocation information, geolocationinstructions, PCI and/or ECGI.

In an embodiment, the managing 410 may include determining neighboringnodes to add to a NCL using the PCI/ECGI and geolocation information.For example, based on the GPS coordinates, it can be decided whether toadd a cell to the NCL immediately, later on, or not at all. In someembodiments, adding a cell may include setting up an X2 interface, inaddition to updating the NCL.

In a further embodiment, the managing 410 may include determiningexisting neighboring nodes to remove from a NCL, based at least in parton the GPS information. For example, in an embodiment, it may bedetermined to remove a node from the NCL if the distance increases theestimated HAPS coverage. In some embodiments, where a minimum distancebetween two terrestrial cells with the same PCI is known, if thisminimum distance is large, then the HAPS may determine to keep neighborrelations longer as this would not create any harm. If the minimumdistance is short, then the HAPS may determine to remove neighborrelations earlier.

In some embodiments, when the HAPS is aware of a PCI confusion, themanaging 410 may include determining, based on the GPS coordinates ofthe cells causing the PCI confusion, to remove the neighbor relation toavoid the PCI confusion. When the PCI confusion is between cells thatare both relevant, the managing 410 may include resolving, provided somerough location information of the UE(s), from the PCI, the ECGI andthereby the correct X2 interface for the handover of the UE(s). Forexample, in an embodiment, the method may include receiving ameasurement report from a UE with the PCI confusion. Rough locationinformation about the UE may be retrieved, for example, based onreported GPS information or based on radio frequency (RF) finger prints(evaluating neighbor measurements from the past). This locationinformation can be used to resolve the PCI, for example, by selectingthe cell whose GPS information has the closest distance to the roughlocation information of the UE. The method may then include initiating aproper handover to the selected target cell.

FIG. 4b illustrates an example flow chart of a method depicting anapplication or implementation of an example embodiment. As illustratedin the example of FIG. 4b , at 1, a terrestrial neighboring cell (e.g.,cell 18 in the example of FIG. 3) may send a configuration updatemessage (e.g., “eNB Configuration Update”) to HAPS. The sending of theconfiguration update message may have already occurred when theneighboring cell (e.g., cell 18) was added. However, the sending of theconfiguration update message may also occur during a later update (e.g.,as specified in 3GPP TS 36.423 and 36.300). In an embodiment, theconfiguration update message may contain PCIs and corresponding ECGIs ofthe neighbor(s) of the neighboring cell (e.g., cell 18), as well as GPScoordinates.

As further illustrated in the example of FIG. 4b , at 2, the HAPS maystore the PCI/ECGI/GPS triples received for relevant terrestrial cells.In one example, relevant cells may refer to cells that are already inthe coverage area or that are in the direction of the movement of theHAPS. In some embodiments, a cell in the opposite direction and/oroutside the coverage area of the HAPS would not be stored as a relevantcell.

At 3, the HAPS may detect that a new cell (e.g., cell 13 in the exampleof FIG. 3, which is stored but not part of the neighbor cell list (NCL)and without X2 interface) enters the coverage area of the HAPS. Thisdetection may be based on the GPS information (the HAPS knows its ownGPS location) and an appropriate coverage prediction. Additionally oralternatively, the detection may be based on distance informationreceived from, e.g., a HAPS manager. If the new cell (e.g., cell 13) iscloser than the minimum distance between two terrestrial cells with samePCI, the HAPS may detect this cell even if it is not yet in the coveragearea (no risk of PCI confusion). Then, at 4, the HAPS may add the newcell to the neighbor cell list (NCL) and set up an X2 interface to thenew cell. The HAPS may also inform the new cell about the new neighborrelation, but this could be considered inherent to the setup of the X2connection. At 5, HAPS and new cell 13 may initiate proper handovers inboth directions (i.e., HAPS→13; 13→HAPS).

In the example of FIG. 4b , at 6, the HAPS may also determine that anexisting cell (e.g., 2) falls out of its coverage area. Then, at 7, theHAPS may remove the existing cell (e.g., 2) from the NCL, and may alsoremove the X2 interface. It is noted that the HAPS may also decide tokeep the cell to be on the safe side, and only remove it later on, whenthe distance is larger than a distance information (e.g., minimumdistance between two terrestrial cells with same PCI). In an embodiment,the HAPS may inform the old cell that the neighbor relation is no longerrelevant (which is inherently done when removing the X2 interface).

According to an embodiment, continuing with FIG. 4b , in the situationof unavoidable PCI confusion (e.g., two terrestrial cells with PCI 3),the GPS information may be used to initiate the handover to the correctcell. For example, at 8, the UE may report measurements with theambiguous PCI. At 9, the HAPS may retrieve rough location informationabout the UE, e.g., based on reported GPS information or based on RFfinger prints (evaluating neighbor measurements from the past). This canbe used to resolve the PCI, e.g., by selecting the cell whose GPSinformation has the closest distance to the rough location informationof the UE. Finally, at 10, the HAPS may initiate a proper handover tothe correct target cell.

In addition to the examples discussed above in detail, the exchange ofgeolocation information or GPS coordinates may be implemented inalternative ways. For instance, in an embodiment, a HAPS may receive alist of (relevant) PCI/ECGI/GPS triples about terrestrial cells from aHAPS manager. This may, for example, replace or supplement the X2information exchange discussed above.

In an embodiment, terrestrial cells may receive a list of (relevant)PCI/ECGI/GPS triples about HAPS cell(s) from its own OAM. In thisembodiment, if the terrestrial cells know the HAPS location, terrestrialcells may follow similar procedures to those described above for HAPS(e.g., FIG. 4). This may have the advantage that less GPS informationhas to be exchanged (much less HAPS than terrestrial cells), but thegeographical HAPS information may have to be updated more often.

According to certain embodiments, PCI collisions and confusions amongHAPS can also be resolved using geometrical considerations (since thepropagation is very predictable). For instance, from the PCI/ECGI/GPStriples received from existing neighbors, a HAPS may be configured todetect if a HAPS with same PCI comes too close. In this case, one of theHAPS may change the PCI. Again, distance information from anothernetwork node, such as a HAPS manager, may assist. For example, thedistance information may include a minimum distance between HAPS withsame PCI.

Table 1 below provides an example how a configuration update message,such as an eNB Configuration Update message (e.g., as specified in 3GPPTS 36.423), can be extended, for example to include GPS information,according to certain embodiments.

TABLE 1 As- IE type signed IE/Group and Semantics Criti- Criti- NamePresence Range reference description cality cality Message Type M 9.2.13YES reject Served Cells 0 . . . Complete list GLOBAL reject To Add<maxCellineNB> of added cells served by the eNB >Served Cell M 9.2.8 — —Information >Neighbour 0 . . . — — Information<maxnoofNeighbours> >>ECGI M ECGI E-UTRAN — — 9.2.14 Cell GlobalIdentifier of the neighbour cell >>PCI M INTEGER Physical Cell — — (0 .. . 503, Identifier of . . .) the neighbour cell >>GPSinfo M GPS GPS — —coordinates coordinates of the neighbour cell >>EARFCN M 9.2.26 DLEARFCN — — for FDD or EARFCN for TDD >>TAC O OCTET Tracking Area YESignore STRING Code (2) >>EARFCN O 9.2.65 DL EARFCN YES reject Extensionfor FDD or EARFCN for TDD. If this IE is present, the value signalled inthe EARFCN IE is ignored. Served Cells 0 . . . Complete list GLOBALreject To Modify <maxCellineNB> of modified cells served by the eNB >OldECGI M ECGI Old E- — — 9.2.14 UTRAN Cell Global Identifier >Served CellM 9.2.8 — — Information >Neighbour 0 . . . — — Information<maxnoofNeighbours> >>ECGI M ECGI E-UTRAN — — 9.2.14 Cell GlobalIdentifier of the neighbour cell >>PCI M INTEGER Physical Cell — — (0 .. . 503, Identifier of . . .) the neighbour cell >>GPSinfo M GPS GPS — —coordinates coordinates of the neighbour cell >>EARFCN M 9.2.26 DLEARFCN — — for FDD or EARFCN for TDD >>TAC O OCTET Tracking Area YESignore STRING Code (2) >>EARFCN O 9.2.65 DL EARFCN YES reject Extensionfor FDD or EARFCN for TDD. If this IE is present, the value signalled inthe EARFCN IE is ignored. >Deactivation O ENUMERATED(deacti- Indicatesthat YES ignore Indication vated, . . .) the concerned cell is switchedoff for energy saving reasons Served Cells 0 . . . Complete list GLOBALreject To Delete <maxCellineNB> of deleted cells served by the eNB >OldECGI M ECGI Old E- 9.2.14 UTRAN Cell Global Identifier of the cell to bedeleted GU Group Id 0 . . . GLOBAL reject To Add List <maxPools> >GUGroup Id M 9.2.20 — — GU Group Id To 0 . . . GLOBAL reject Delete List<maxPools> >GU Group Id M 9.2.20 — — Coverage 0 . . . List of cellsGLOBAL reject Modification <maxCellineNB> with modified Listcoverage >ECGI M ECGI E-UTRAN 9.2.14 Cell Global Identifier of the cellto be modified >Cell Coverage M INTEGER Value ‘0’ State (0 . . . 15,indicates that . . .) the cell is inactive. Other values Indicates thatthe cell is active and also indicates the coverage configuration of theconcerned cell >Cell O ENUMERATED(pre- Indicates the Deployment change-Cell Coverage Status notification, State is Indicator . . .) planned tobe used at the next reconfiguration >Cell Replacing C- InfoifCellDeploymentStatusIndicatorPresent >>Replacing 0 . . . Cells<maxCellineNB> >>>ECGI ECGI E-UTRAN 9.2.14 Cell Global Identifier of acell that may replace all or part of the coverage of the cell to bemodified

FIG. 5a illustrates an example of an apparatus 10 according to anembodiment. In an embodiment, apparatus 10 may be a node, host, orserver in a communications network or serving such a network. Forexample, apparatus 10 may be a satellite, base station, a Node B, anevolved Node B (eNB), 5G Node B or access point, next generation Node B(NG-NB or gNB), high altitude platform station (HAPS), IAB node, and/orWLAN access point, associated with a radio access network, such as a LTEnetwork, 5G or NR. In example embodiments, apparatus 10 may be or mayinclude a NG-RAN node, an eNB in LTE, gNB in 5G, a HAPS, or the like.

It should be understood that, in some example embodiments, apparatus 10may be comprised of an edge cloud server as a distributed computingsystem where the server and the radio node may be stand-aloneapparatuses communicating with each other via a radio path or via awired connection, or where they may be located in a same entitycommunicating via a wired connection. For instance, in certain exampleembodiments where apparatus 10 represents a gNB, it may be configured ina central unit (CU) and distributed unit (DU) architecture that dividesthe gNB functionality. In such an architecture, the CU may be a logicalnode that includes gNB functions such as transfer of user data, mobilitycontrol, radio access network sharing, positioning, and/or sessionmanagement, etc. The CU may control the operation of DU(s) over afront-haul interface. The DU may be a logical node that includes asubset of the gNB functions, depending on the functional split option.It should be noted that one of ordinary skill in the art wouldunderstand that apparatus 10 may include components or features notshown in FIG. 5 a.

As illustrated in the example of FIG. 5a , apparatus 10 may include aprocessor 12 for processing information and executing instructions oroperations. Processor 12 may be any type of general or specific purposeprocessor. In fact, processor 12 may include one or more ofgeneral-purpose computers, special purpose computers, microprocessors,digital signal processors (DSPs), field-programmable gate arrays(FPGAs), application-specific integrated circuits (ASICs), andprocessors based on a multi-core processor architecture, as examples.While a single processor 12 is shown in FIG. 5a , multiple processorsmay be utilized according to other example embodiments. For example, itshould be understood that, in certain embodiments, apparatus 10 mayinclude two or more processors that may form a multiprocessor system(e.g., in this case processor 12 may represent a multiprocessor) thatmay support multiprocessing. In some embodiments, the multiprocessorsystem may be tightly coupled or loosely coupled (e.g., to form acomputer cluster).

Processor 12 may perform functions associated with the operation ofapparatus 10, which may include, for example, precoding of antennagain/phase parameters, encoding and decoding of individual bits forminga communication message, formatting of information, and overall controlof the apparatus 10, including processes related to management ofcommunication resources.

Apparatus 10 may further include or be coupled to a memory 14 (internalor external), which may be coupled to processor 12, for storinginformation and instructions that may be executed by processor 12.Memory 14 may be one or more memories and of any type suitable to thelocal application environment, and may be implemented using any suitablevolatile or nonvolatile data storage technology such as asemiconductor-based memory device, a magnetic memory device and system,an optical memory device and system, fixed memory, and/or removablememory. For example, memory 14 can be comprised of any combination ofrandom access memory (RAM), read only memory (ROM), static storage suchas a magnetic or optical disk, hard disk drive (HDD), or any other typeof non-transitory machine or computer readable media. The instructionsstored in memory 14 may include program instructions or computer programcode that, when executed by processor 12, enable the apparatus 10 toperform tasks as described herein.

In an embodiment, apparatus 10 may further include or be coupled to(internal or external) a drive or port that is configured to accept andread an external computer readable storage medium, such as an opticaldisc, USB drive, flash drive, or any other storage medium. For example,the external computer readable storage medium may store a computerprogram or software for execution by processor 12 and/or apparatus 10.

In some embodiments, apparatus 10 may also include or be coupled to oneor more antennas 15 for transmitting and receiving signals and/or datato and from apparatus 10. Apparatus 10 may further include or be coupledto a transceiver 18 configured to transmit and/or receive information.The transceiver 18 may include, for example, a plurality of radiointerfaces that may be coupled to the antenna(s) 15. In certainembodiments, the radio interfaces may correspond to a plurality of radioaccess technologies including one or more of GSM, NB-IoT, LTE, 5G, WLAN,Bluetooth, BT-LE, NFC, radio frequency identifier (RFID), ultrawideband(UWB), MulteFire, and/or the like. According to an example embodiment,the radio interface may include components, such as filters, converters(e.g., digital-to-analog converters and the like), mappers, a FastFourier Transform (FFT) module, and/or the like, e.g., to generatesymbols or signals for transmission via one or more downlinks and toreceive symbols (e.g., via an uplink).

As such, transceiver 18 may be configured to modulate information on toa carrier waveform for transmission by the antenna(s) 15 and todemodulate information received via the antenna(s) 15 for furtherprocessing by other elements of apparatus 10. In other exampleembodiments, transceiver 18 may be capable of transmitting and receivingsignals or data directly. Additionally or alternatively, in someembodiments, apparatus 10 may include an input and/or output device (I/Odevice).

In an embodiment, memory 14 may store software modules that providefunctionality when executed by processor 12. The modules may include,for example, an operating system that provides operating systemfunctionality for apparatus 10. The memory may also store one or morefunctional modules, such as an application or program, to provideadditional functionality for apparatus 10. The components of apparatus10 may be implemented in hardware, or as any suitable combination ofhardware and software.

According to some embodiments, processor 12 and memory 14 may beincluded in or may form a part of processing circuitry or controlcircuitry. In addition, in some embodiments, transceiver 18 may beincluded in or may form a part of transceiver circuitry.

As used herein, the term “circuitry” may refer to hardware-onlycircuitry implementations (e.g., analog and/or digital circuitry),combinations of hardware circuits and software, combinations of analogand/or digital hardware circuits with software/firmware, any portions ofhardware processor(s) with software (including digital signalprocessors) that work together to cause an apparatus (e.g., apparatus10) to perform various functions, and/or hardware circuit(s) and/orprocessor(s), or portions thereof, that use software for operation butwhere the software may not be present when it is not needed foroperation. As a further example, as used herein, the term “circuitry”may also cover an implementation of merely a hardware circuit orprocessor (or multiple processors), or portion of a hardware circuit orprocessor, and its accompanying software and/or firmware. The termcircuitry may also cover, for example, a baseband integrated circuit ina server, cellular network node or device, or other computing or networkdevice.

As introduced above, in certain embodiments, apparatus 10 may be anetwork node or RAN node, such as a base station, access point, Node B,eNB, gNB, HAPS, IAB node, WLAN access point, or the like. For example,in some embodiments, apparatus 10 may be configured to perform one ormore of the processes depicted in any of the flow charts or signalingdiagrams described herein, such as those illustrated in FIG. 4a or 4 b.In some embodiments, as discussed herein, apparatus 10 may be configuredto perform a procedure relating to the management of neighbor networknode relations and/or coordinating PCIs.

According to this embodiment, apparatus 10 may be controlled by memory14 and processor 12 to receive geolocation information, such as GPScoordinates, for one or more network node(s). The network node(s) may bea terrestrial base station or HAPS. In some embodiments, apparatus 10may be controlled by memory 14 and processor 12 to receive thegeolocation information from an other network node, such as anotherHAPS, a terrestrial base station, a centralized entity, or a HAPSmanager. For example, the received geolocation information may includethe geolocation information of the other network node and/or thegeolocation information of nodes neighboring the other network node. Asan example, apparatus 10 may be controlled by memory 14 and processor 12to receive the geolocation information, from a terrestrial base stationor eNB/gNB, GPS coordinates of neighboring terrestrial base stations oreNBs/gNBs, along with the PCI/ECGI and the GPS coordinates of theterrestrial base station/eNB/gNB. In certain embodiments, apparatus 10may be controlled by memory 14 and processor 12 to store the receivedgeolocation information.

In an embodiment, apparatus 10 may be controlled by memory 14 andprocessor 12 to manage relations of neighbor network nodes and/or toresolve PCI problems, using at least the received geolocationinformation. For example, the PCI problems may include PCI collisionand/or PCI confusion. According to some embodiments, apparatus 10 may becontrolled by memory 14 and processor 12 to use the received geolocationinformation to add or remove neighbor relations in terms of PCI/ECGIpairs or PCI/IP address pairs and/or to add or remove X2 connections.

In some embodiments, apparatus 10 may be controlled by memory 14 andprocessor 12 to receive geometrical instruction, such as a minimum ormaximum distance, from another network node, such as a HAPS manager orOAM, which may assist in determining the strategy to manage neighbourrelations. In an embodiment, apparatus 10 may be controlled by memory 14and processor 12 to inform one or more network node(s) when theneighbour relation to those network node(s) is no longer relevant. Forinstance, the neighbor relation may be considered no longer relevantwhen the network node(s) are no longer in the coverage of the apparatus10 or are not in the direction of movement of the apparatus 10.According to certain embodiments, apparatus 10 may be controlled bymemory 14 and processor 12 to receive the geolocation information and/orgeolocation instruction in a configuration update message via X2interface. For example, in an embodiment, the X2 information inconfiguration update message may be extended to include, in addition toPCI and ECGI, GPS coordinates and/or geolocation instructions. In someembodiments, apparatus 10 may be controlled by memory 14 and processor12 to store the geolocation information, geolocation instructions, PCIand/or ECGI.

In an embodiment, apparatus 10 may be controlled by memory 14 andprocessor 12 to determine neighboring nodes to add to a NCL using thePCI/ECGI and geolocation information. For example, based on the GPScoordinates, apparatus 10 may be controlled by memory 14 and processor12 to decide whether to add a cell to the NCL immediately, later on, ornot at all. In some embodiments, adding a cell may include setting up anX2 interface, in addition to updating the NCL.

In a further embodiment, apparatus 10 may be controlled by memory 14 andprocessor 12 to determine existing neighboring nodes to remove from aNCL, based at least in part on the geolocation information. For example,in an embodiment, apparatus 10 may be controlled by memory 14 andprocessor 12 to determine to remove a node from the NCL if the distanceincreases the estimated coverage area of apparatus 10. In someembodiments, where a minimum distance between two terrestrial cells withthe same PCI is known and if this minimum distance is large, thenapparatus 10 may be controlled by memory 14 and processor 12 todetermine to keep neighbor relations longer as this would not create anyissues. If the minimum distance is short, then apparatus 10 may becontrolled by memory 14 and processor 12 to determine to remove neighborrelations earlier.

In some embodiments, when the apparatus 10 is aware of a PCI confusion,apparatus 10 may be controlled by memory 14 and processor 12 todetermine, based on the GPS coordinates of the cells causing the PCIconfusion, to remove the neighbor relation to avoid the PCI confusion.When the PCI confusion is between cells that are both relevant,apparatus 10 may be controlled by memory 14 and processor 12 to resolve,provided some rough location information of the UE(s), the ECGI andthereby determine the correct X2 interface for the handover of theUE(s). For example, in an embodiment, apparatus 10 may be controlled bymemory 14 and processor 12 to receive a measurement report from a UEwith the PCI confusion. Rough location information about the UE may beretrieved, for example, based on reported GPS information or based onradio frequency (RF) finger prints (evaluating neighbor measurementsfrom the past). In this embodiment, apparatus 10 may be controlled bymemory 14 and processor 12 to, with the location information, resolvethe PCI, for example, by selecting the cell whose GPS information hasthe closest distance to the rough location information of the UE. In anembodiment, apparatus 10 may then be controlled by memory 14 andprocessor 12 to initiate a proper handover to the selected target cell.

FIG. 5b illustrates an example of an apparatus 20 according to anotherembodiment. In an embodiment, apparatus 20 may be a node or element in acommunications network or associated with such a network, such as a UE,mobile equipment (ME), mobile station, mobile device, stationary device,IoT device, or other device. As described herein, UE may alternativelybe referred to as, for example, a mobile station, mobile equipment,mobile unit, mobile device, user device, subscriber station, wirelessterminal, tablet, smart phone, IoT device, sensor or NB-IoT device, orthe like. As one example, apparatus 20 may be implemented in, forinstance, a wireless handheld device, a wireless plug-in accessory, orthe like.

In some example embodiments, apparatus 20 may include one or moreprocessors, one or more computer-readable storage medium (for example,memory, storage, or the like), one or more radio access components (forexample, a modem, a transceiver, or the like), and/or a user interface.In some embodiments, apparatus 20 may be configured to operate using oneor more radio access technologies, such as GSM, LTE, LTE-A, NR, 5G,WLAN, WiFi, NB-IoT, Bluetooth, NFC, MulteFire, and/or any other radioaccess technologies. It should be noted that one of ordinary skill inthe art would understand that apparatus 20 may include components orfeatures not shown in FIG. 5 b.

As illustrated in the example of FIG. 5b , apparatus 20 may include orbe coupled to a processor 22 for processing information and executinginstructions or operations. Processor 22 may be any type of general orspecific purpose processor. In fact, processor 22 may include one ormore of general-purpose computers, special purpose computers,microprocessors, digital signal processors (DSPs), field-programmablegate arrays (FPGAs), application-specific integrated circuits (ASICs),and processors based on a multi-core processor architecture, asexamples. While a single processor 22 is shown in FIG. 5b , multipleprocessors may be utilized according to other embodiments. For example,it should be understood that, in certain embodiments, apparatus 20 mayinclude two or more processors that may form a multiprocessor system(e.g., in this case processor 22 may represent a multiprocessor) thatmay support multiprocessing. In certain embodiments, the multiprocessorsystem may be tightly coupled or loosely coupled (e.g., to form acomputer cluster).

Processor 22 may perform functions associated with the operation ofapparatus 20 including, as some examples, precoding of antennagain/phase parameters, encoding and decoding of individual bits forminga communication message, formatting of information, and overall controlof the apparatus 20, including processes related to management ofcommunication resources.

Apparatus 20 may further include or be coupled to a memory 24 (internalor external), which may be coupled to processor 22, for storinginformation and instructions that may be executed by processor 22.Memory 24 may be one or more memories and of any type suitable to thelocal application environment, and may be implemented using any suitablevolatile or nonvolatile data storage technology such as asemiconductor-based memory device, a magnetic memory device and system,an optical memory device and system, fixed memory, and/or removablememory. For example, memory 24 can be comprised of any combination ofrandom access memory (RAM), read only memory (ROM), static storage suchas a magnetic or optical disk, hard disk drive (HDD), or any other typeof non-transitory machine or computer readable media. The instructionsstored in memory 24 may include program instructions or computer programcode that, when executed by processor 22, enable the apparatus 20 toperform tasks as described herein.

In an embodiment, apparatus 20 may further include or be coupled to(internal or external) a drive or port that is configured to accept andread an external computer readable storage medium, such as an opticaldisc, USB drive, flash drive, or any other storage medium. For example,the external computer readable storage medium may store a computerprogram or software for execution by processor 22 and/or apparatus 20.

In some embodiments, apparatus 20 may also include or be coupled to oneor more antennas 25 for receiving a downlink signal and for transmittingvia an uplink from apparatus 20. Apparatus 20 may further include atransceiver 28 configured to transmit and receive information. Thetransceiver 28 may also include a radio interface (e.g., a modem)coupled to the antenna 25. The radio interface may correspond to aplurality of radio access technologies including one or more of GSM,LTE, LTE-A, 5G, NR, WLAN, NB-IoT, Bluetooth, BT-LE, NFC, RFID, UWB, andthe like. The radio interface may include other components, such asfilters, converters (for example, digital-to-analog converters and thelike), symbol demappers, signal shaping components, an Inverse FastFourier Transform (IFFT) module, and the like, to process symbols, suchas OFDMA symbols, carried by a downlink or an uplink.

For instance, transceiver 28 may be configured to modulate informationon to a carrier waveform for transmission by the antenna(s) 25 anddemodulate information received via the antenna(s) 25 for furtherprocessing by other elements of apparatus 20. In other embodiments,transceiver 28 may be capable of transmitting and receiving signals ordata directly. Additionally or alternatively, in some embodiments,apparatus 20 may include an input and/or output device (I/O device). Incertain embodiments, apparatus 20 may further include a user interface,such as a graphical user interface or touchscreen.

In an embodiment, memory 24 stores software modules that providefunctionality when executed by processor 22. The modules may include,for example, an operating system that provides operating systemfunctionality for apparatus 20. The memory may also store one or morefunctional modules, such as an application or program, to provideadditional functionality for apparatus 20. The components of apparatus20 may be implemented in hardware, or as any suitable combination ofhardware and software. According to an example embodiment, apparatus 20may optionally be configured to communicate with apparatus 10 via awireless or wired communications link 70 according to any radio accesstechnology, such as NR.

According to some embodiments, processor 22 and memory 24 may beincluded in or may form a part of processing circuitry or controlcircuitry. In addition, in some embodiments, transceiver 28 may beincluded in or may form a part of transceiving circuitry.

As discussed above, according to some embodiments, apparatus 20 may be aUE, mobile device, mobile station, ME, IoT device and/or NB-IoT device,for example. According to certain embodiments, apparatus 20 may becontrolled by memory 24 and processor 22 to perform the functionsassociated with example embodiments described herein. For example, insome embodiments, apparatus 20 may be configured to perform one or moreof the processes depicted in any of the flow charts or signalingdiagrams described herein, such as those illustrated in FIG. 4a and FIG.4b . In certain embodiments, apparatus 20 may be configured to perform aprocedure relating to the management of neighbor network node relationsand/or coordinating PCIs, for instance. For example, in someembodiments, apparatus 20 may be controlled by memory 24 and processor22 to provide measurement report(s) to one or more network nodes, suchas base stations, eNBs, gNBs, NG-RAN nodes, or HAPS, for example.

Therefore, certain example embodiments provide several technologicalimprovements, enhancements, and/or advantages over existingtechnological processes and constitute an improvement at least to thetechnological field of wireless network control and management. Forexample, certain embodiments enable most functionality can beimplemented in a HAPS, thereby minimizing impact to the terrestrialnetwork, base stations or cells. According to certain embodiments,terrestrial cells only need to add GPS coordinates to the existing eNBconfiguration update. Furthermore, example embodiments are able to solveall PCI problems. In addition, UEs are not impacted and ECGI reading isavoided. Accordingly, the use of certain example embodiments results inimproved functioning of communications networks and their nodes, such asbase stations, eNBs, gNBs, and/or UEs or mobile stations.

In some example embodiments, the functionality of any of the methods,processes, signaling diagrams, algorithms or flow charts describedherein may be implemented by software and/or computer program code orportions of code stored in memory or other computer readable or tangiblemedia, and executed by a processor.

In some example embodiments, an apparatus may be included or beassociated with at least one software application, module, unit orentity configured as arithmetic operation(s), or as a program orportions of it (including an added or updated software routine),executed by at least one operation processor. Programs, also calledprogram products or computer programs, including software routines,applets and macros, may be stored in any apparatus-readable data storagemedium and may include program instructions to perform particular tasks.

A computer program product may include one or more computer-executablecomponents which, when the program is run, are configured to carry outsome example embodiments. The one or more computer-executable componentsmay be at least one software code or portions of code. Modifications andconfigurations required for implementing functionality of an exampleembodiment may be performed as routine(s), which may be implemented asadded or updated software routine(s). In one example, softwareroutine(s) may be downloaded into the apparatus.

As an example, software or computer program code or portions of code maybe in source code form, object code form, or in some intermediate form,and it may be stored in some sort of carrier, distribution medium, orcomputer readable medium, which may be any entity or device capable ofcarrying the program. Such carriers may include a record medium,computer memory, read-only memory, photoelectrical and/or electricalcarrier signal, telecommunications signal, and/or software distributionpackage, for example. Depending on the processing power needed, thecomputer program may be executed in a single electronic digital computeror it may be distributed amongst a number of computers. The computerreadable medium or computer readable storage medium may be anon-transitory medium.

In other example embodiments, the functionality may be performed byhardware or circuitry included in an apparatus, for example through theuse of an application specific integrated circuit (ASIC), a programmablegate array (PGA), a field programmable gate array (FPGA), or any othercombination of hardware and software. In yet another example embodiment,the functionality may be implemented as a signal, such as a non-tangiblemeans, that can be carried by an electromagnetic signal downloaded fromthe Internet or other network.

According to an example embodiment, an apparatus, such as a node,device, or a corresponding component, may be configured as circuitry, acomputer or a microprocessor, such as single-chip computer element, oras a chipset, which may include at least a memory for providing storagecapacity used for arithmetic operation(s) and/or an operation processorfor executing the arithmetic operation(s).

One having ordinary skill in the art will readily understand that theexample embodiments as discussed above may be practiced with proceduresin a different order, and/or with hardware elements in configurationswhich are different than those which are disclosed. Therefore, althoughsome embodiments have been described based upon these exampleembodiments, it would be apparent to those of skill in the art thatcertain modifications, variations, and alternative constructions wouldbe apparent, while remaining within the spirit and scope of exampleembodiments.

PARTIAL GLOSSARY

ANR Automatic Neighbor Relation ECGI Enhanced Cell Global Identifier eNBLTE Base Station gNB 5G or Next Generation NodeB NG-RAN NextGeneration-Radio Access Network NR New Radio GPS Global PositioningService HAPS High Altitude Platform Systems/Station IP Internet ProtocolNCL Neighbor Cell List OAM Operation and Maintenance PCI Physical CellIdentifier

What is claimed is:
 1. A method, comprising: receiving, at a firstnetwork node, geolocation information for at least one second networknode; managing, by the first network node, relations of neighbor networknodes of the first network node and/or the at least one second networknode; and resolving physical cell identifier problems using thegeolocation information.
 2. The method according to claim 1, wherein thefirst network node comprises a high altitude platform station or flyingbase station, and wherein the at least one second network node comprisesat least one terrestrial base station or at least one high altitudeplatform station or flying base station.
 3. The method according toclaim 1 wherein the physical cell identifier problems comprise at leastone of physical cell identifier collision or physical cell identifierconfusion.
 4. The method according to claim 1, wherein the receivingfurther comprises: receiving the geolocation information from a thirdnetwork node, wherein the third network node comprises at least one ofhigh altitude platform station or flying base station, a terrestrialbase station, a centralized entity, or a high altitude platform stationmanager.
 5. The method according to claim 1, wherein the geolocationinformation comprises global positioning service coordinates of the atleast one second network node, and wherein the receiving furthercomprises: receiving the global positioning service coordinates of theat least one second network node; and receiving the physical cellidentifier and enhanced cell global identifier of the at least onesecond network node.
 6. The method according to claim 1, furthercomprising: storing the geolocation information, global positioningservice coordinates, and/or physical cell identifier and enhanced cellglobal identifier of the at least one second network node.
 7. The methodaccording to claim 1, further comprising: receiving geometricalinstruction from a fourth network node to assist in determining astrategy to manage the neighbor relations, wherein the fourth networknode comprises at least one of a high altitude platform station manageror operation and maintenance.
 8. An apparatus, comprising: at least oneprocessor; and at least one memory comprising computer program code, theat least one memory and computer program code are configured, with theat least one processor, to cause the apparatus at least to: receivegeolocation information for at least one first network node; managerelations of neighbor network nodes of the apparatus and/or the at leastone first network node; and resolve physical cell identifier problemsusing the geolocation information.
 9. The apparatus according to claim8, wherein the apparatus comprises a high altitude platform station orflying base station, and wherein the at least one first network nodecomprises at least one terrestrial base station or at least one highaltitude platform station or flying base station.
 10. The apparatusaccording to claim 8, wherein the physical cell identifier problemscomprise at least one of physical cell identifier collision or physicalcell identifier confusion.
 11. The apparatus according to claim 8,wherein the at least one memory and computer program code configured toreceive geolocation information are further configured, with the atleast one processor, to cause the apparatus at least to: receive thegeolocation information from a second network node, wherein the secondnetwork node comprises at least one of high altitude platform station orflying base station, a terrestrial base station, a centralized entity,or a high altitude platform station manager.
 12. The apparatus accordingto claim 11, wherein the second network node and the at least one firstnetwork node are the same network node.
 13. The apparatus according toclaim 8, wherein the geolocation information comprises globalpositioning service coordinates of the at least one first network node,and wherein the at least one memory and computer program code configuredto receive geolocation information are further configured, with the atleast one processor, to cause the apparatus at least to: receive theglobal positioning service coordinates of the at least one first networknode; and receive the physical cell identifier and enhanced cell globalidentifier of the at least one first network node.
 14. The apparatusaccording to claim 8, wherein the at least one memory and computerprogram code are further configured, with the at least one processor, tocause the apparatus at least to: store the geolocation information,global positioning service coordinates, and/or physical cell identifierand enhanced cell global identifier of the at least one first networknode.
 15. The apparatus according to claim 8, wherein the at least onememory and computer program code are further configured, with the atleast one processor, to cause the apparatus at least to: receivegeometrical instruction from a third network node to assist indetermining a strategy to manage the neighbor relations, wherein thethird network node comprises at least one of a high altitude platformstation manager or operation and maintenance.
 16. The apparatusaccording to claim 8, wherein the at least one memory and computerprogram code configured to receive geolocation information are furtherconfigured, with the at least one processor, to cause the apparatus atleast to: receive the geolocation information and/or geometricinstruction in a configuration update message via X2 interface.
 17. Theapparatus according to claim 8, wherein the at least one memory andcomputer program code configured to manage relations of neighbor networknodes are further configured, with the at least one processor, to causethe apparatus at least to: use the geolocation information to perform atleast one of: adding or removing neighbor relations between theapparatus and the at least one first network node; and adding orremoving X2 connections between the apparatus and the at least one firstnetwork node.
 18. The apparatus according to claim 8, wherein the atleast one memory and computer program code configured to managerelations of neighbor network nodes are further configured, with the atleast one processor, to cause the apparatus at least to: use globalpositioning service coordinates, physical cell identifier and enhancedcell global identifier of the at least one first network node todetermine whether the at least one first network node is a relevantneighbor of the apparatus.
 19. The apparatus according to claim 8,wherein the at least one memory and computer program code are furtherconfigured, with the at least one processor, to cause the apparatus atleast to: inform the at least one first network node when a neighborrelation is no longer relevant.
 20. A computer program embodied on anon-transitory computer-readable storage medium, the computer programcomprising program code for controlling a process to execute a process,the process comprising: receiving, at a first network node, geolocationinformation for at least one second network node; managing, by the firstnetwork node, relations of neighbor network nodes of the first networknode and/or the at least one second network; and resolving physical cellidentifier problems using the geolocation information.